Cleanup: get rid of req_null (#8798)

Author: asfernandes

src/common/classes/TriState.h

@@ -34,8 +34,14 @@ namespace Firebird {
 class TriState
 {
 public:
-	TriState() noexcept;
-	explicit TriState(bool input) noexcept;
+	static constexpr TriState empty() noexcept
+	{
+		return TriState();
+	}
+
+public:
+	constexpr TriState() noexcept;
+	explicit constexpr TriState(bool input) noexcept;
 
 	bool operator ==(const TriState& o) const noexcept
 	{
@@ -62,13 +68,13 @@ class TriState
 };
 
 // The var is left uninitialized.
-inline TriState::TriState() noexcept
+inline constexpr TriState::TriState() noexcept
 	: m_init(false), m_val(false)
 {
 }
 
 // The var is initialized to the explicit value.
-inline TriState::TriState(bool input) noexcept
+inline constexpr TriState::TriState(bool input) noexcept
 	: m_init(true), m_val(input)
 {
 }

src/dsql/AggNodes.cpp

@@ -388,7 +388,7 @@ bool AggNode::aggPass(thread_db* tdbb, Request* request) const
 	if (arg)
 	{
 		desc = EVL_expr(tdbb, request, arg);
-		if (request->req_flags & req_null)
+		if (!desc)
 			return false;
 
 		if (distinct)
@@ -597,7 +597,7 @@ void AnyValueAggNode::aggPass(thread_db* tdbb, Request* request, dsc* desc) cons
 	{
 		const auto argValue = EVL_expr(tdbb, request, arg);
 
-		if (!(request->req_flags & req_null))
+		if (!argValue)
 			EVL_make_value(tdbb, argValue, impure);
 	}
 
@@ -1037,7 +1037,7 @@ void ListAggNode::aggPass(thread_db* tdbb, Request* request, dsc* desc) const
 	{
 		const dsc* const delimiterDesc = EVL_expr(tdbb, request, delimiter);
 
-		if (request->req_flags & req_null)
+		if (!delimiterDesc)
 		{
 			// Mark the result as NULL.
 			impure->vlu_desc.dsc_dtype = 0;
@@ -2031,11 +2031,11 @@ bool CorrAggNode::aggPass(thread_db* tdbb, Request* request) const
 	dsc* desc2 = NULL;
 
 	desc = EVL_expr(tdbb, request, arg);
-	if (request->req_flags & req_null)
+	if (!desc)
 		return false;
 
 	desc2 = EVL_expr(tdbb, request, arg2);
-	if (request->req_flags & req_null)
+	if (!desc2)
 		return false;
 
 	++impure->vlux_count;
@@ -2307,11 +2307,11 @@ bool RegrAggNode::aggPass(thread_db* tdbb, Request* request) const
 	dsc* desc2 = NULL;
 
 	desc = EVL_expr(tdbb, request, arg);
-	if (request->req_flags & req_null)
+	if (!desc)
 		return false;
 
 	desc2 = EVL_expr(tdbb, request, arg2);
-	if (request->req_flags & req_null)
+	if (!desc2)
 		return false;
 
 	++impure->vlux_count;
@@ -2559,12 +2559,10 @@ void RegrCountAggNode::aggInit(thread_db* tdbb, Request* request) const
 
 bool RegrCountAggNode::aggPass(thread_db* tdbb, Request* request) const
 {
-	EVL_expr(tdbb, request, arg);
-	if (request->req_flags & req_null)
+	if (!EVL_expr(tdbb, request, arg))
 		return false;
 
-	EVL_expr(tdbb, request, arg2);
-	if (request->req_flags & req_null)
+	if (!EVL_expr(tdbb, request, arg2))
 		return false;
 
 	impure_value_ex* impure = request->getImpure<impure_value_ex>(impureOffset);